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weathering and soil formation - Coggle Diagram
weathering and soil formation
Four spheres
Hydrosphere
all the water
Lithosphere
the solid earth
Biosphere
all life
Atmosphere
gases(the air)
The Two Forces
Internal force
Eternal force
Minerals
Naturally occurring
solid
has a specific chemical composition
definite crystalline structure
Rocks
Solid
Inorganic
Naturally formed
no particular atomic structure and chemical composition
Types of Rocks
Igneous rock
are formed by solidification if molten rocks ( lava )
A.K.A plutonic or volcanic rocks
Sedimentary rock
when combinations of rock fragments , seashells and chemicals are compressed in layers and hardened sedimentary rocks are formed
are usually found near river deposits
Metamorphic rocks
when other rocks are changed by heat pressure and chemical action , they form metamorphic rocks
The Rock Cycle
Soil
is a natural body of mineral and organic material
Has no definite and constant composition
contains decayed plants and animals
consists of silica, clay and, chalk
organic matter called humus
SOIL PROFILE
O-horizon : topmost layer
A-horizon : topsoil, rich in humus and minerals. contains nutrients
B-horizon: subsoil, no humus, has.mierals ; gravel; silt; clay and sand
C-horizon: weathers parent rock
D-horizon: bedrock
Factors dependent on soil formartion
Nature of parent rock: color and texrure, determines chemical propeties, mineral content penitration of soil
Relief of area: altitude and slope, determines accumulation of soil
Climate: temperature and rainfall= rate of weathering and erosion
Vegetation: determines the quantity of hummus and microorganisms + flora and fauna and microorganisms
Time: 1000 years for 2.5 I'm of soil, determines thickness
